1. Field of the Invention
The present invention relates to a method for the color evaluation of pattern models of textile, decoration or packaging printing, in which a pattern model having a plurality of pattern colors is scanned line-by-line in order to obtain primary color measuring signals and is displayed on a color monitor, controlled by video color signals prior to printing the pattern on a printing medium and to a color evaluation device.
2. Description of the Prior Art
Whereas the application of color on a printing medium in multi-color printing occurs by means of the overprinting of different components of the separation colors magenta, cyan and yellow, every color to be printed in fabric, decoration or packaging printing is mixed before the printing process and then separately transferred to the printing medium. The pattern models for the mentioned printing types, for example, exhibit color areas of different coloration residing separately next to one another, whereby the individual color areas have differing color saturation and/or brightness (gradation color areas). In this case, analogue graduated color separations must be produced for the individual pattern colors with the assistance of a color scanner, which half tone color separations supply both a statement concerning a local distribution of the colors in the pattern modules, i.e. essentially over the geometric pattern, as well as a statement concerning the amount of color.
In such a color scanner, three primary color measuring signals are obtained by means of point-by-point and line-by-line optoelectronic pattern scanning, which primary color measuring signals represent the color components red, green and blue of the scanned image points. A color recognition circuit has the primary color measuring signals applied thereto and selects the individual pattern colors and generates specific color separation signals for the pattern colors perceived, which specific color separation signals modulate the brightness of lamps as recording elements. The lamps expose a recording medium, in the form of films, point-by-point and line-by-line, and the films, after development, represent the desired screened or un-screened color separations for the production of the printing forms.
For the printing process, printing colors changed with respect to pattern colors can be assigned to the color separations. Often, the same fabric design is to be printed with different color combinations (color variations), whereby only some of the pattern colors are respectively changed while others are retained.
To this end, it is desirable to examine the printing result with respect to design, coloration and color composition before printing, in order to be able, if necessary, to correct colors and to judge different color locations without having to first produce a printing proof for the purpose of monitoring.
Color display devices for true-color simulation of printing processes are already known in the art and provide a visual evaluation of the final product. In such a color display device, a pattern is scanned in terms of video by means of a color camera and is again recorded on a color monitor. The color signals arising upon scanning are converted in a color computer into corrected color separation signals. A printing simulation computer connected to the output of the color computer, which specifically considers the printing parameters for the multi-color printing, converts the corrected color separation signals into control signals for the color monitor in such a manner that the display of the pattern on the picture screen of the color monitor produces the same colored impression as the multi-color printing. These known color display devices are specifically designed for multi-color printing, but are not designed for the concerns of fabric, decoration and packing printing. Although a color correction must be carried out with the color display devices, this is only effective for wide coverage. Targeted color changes of a single color area can only be imperfectly executed since the selectivity of the known color computers does not cover the desired, narrower correction areas which differ from pattern-to-pattern. Moreover, there is no possibility to simultaneously evaluate different color variations.